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http://www.mobiquitynetworks.com/sites/32/Mobiquity_Presentation.pdf
http://www.mobiquitynetworks.com/network.html
Enjoy!

Very interesting. I wonder if the antenna arrays do a complete connection with the tags? I suppose this isn’t necessary if they are taking advantage of the advertisement packets that the Bluetooth Low energy devices can transmit. It’s all a matter of capturing the RSSI values and doing a triangulation with it. And the mobile tags can respond to the antennas with a little more of information … this would perhaps further increase the 3d location resolution of the system.
Considering the comment from ‘hm’ about using PLC I think this isn’t necessary as the article mentions using the WiFi hotspots which already are 2.4GHz radio’s. but wouldn’t this be a new product of it’s one? I haven’t heard about a WiFi router with Bluetooth Protocol capabilities. Only in mobile phones.

Indoor navigation is obviously a path to go. I was thinking if there was a map in a shopping mall to help me to locate shop a while back.
Coincidentally, I've got news from Google is offering indoor navigation yesterday. I'm glad to learn that Nokia is walking on the same path. Using combination of bluetooth and WiFi and establishing a standard seem to be the right path. Bluetooth provides a better granularity while WiFi provides a coverage of a larger area.
Today's Bluetooth doesn't automatically pair up to bluetooth around it. I don't think the smartphone or tablet automatically accept any data from a bluetooth transmitter nearby. There seemingly are changes in driver, firmware and, possibly hardware. I can't wait to learn more about the detail. :)

Interestingly, Google Maps just announced an indoor feature supported in Android.
See http://googleblog.blogspot.com/2011/11/new-frontier-for-google-maps-mapping.html
Looks like Nokia may need to get some help from Microsoft accelerating its program!